Synthesis and characterization of a novel terpolymer based on L-lactide, glycolide, and trimethylene carbonate for specific medical applications

The bioresorbable new terpolymers of L-lactide, glycolide, and trimethylene carbonate were synthesized via ring-opening polymerization reaction of the cyclic monomers using Stannous octoate as initiator. Glycolide and L-lactide were prepared from their parent acids and then purified by multiple re-crystallization from ethyl acetate. The thermal and mechanical properties of this polymer were characterized by means of thermogravimetry, differential scanning calorimetry, stressstrain measurements, and dynamic mechanical analysis. The glass transition temperature of the terpolymers changed from 33 to 51 degrees C with composition in a predictable manner. The rheological properties of copolymers and molecular weight of each copolymer were determined showing good processability for making fibers. Using a mini-extruder, it was possible to produce some filaments. The filaments produced at 140 degrees C had appropriate ductility. The in vitro measurements, specifying the biological properties were also carried out. The sample with monomer composition LLA:GA:TMC=60:34:6 showed a slower degradation rate than the one with LLA:GA:TMC=54:34:12. The low-toxicity bioresorbable terpolymers with good rheological and in vitro properties are the promising new materials for biomedical applications specially a new suture formulation. Copyright (C) 2011 John Wiley & Sons, Ltd.